link(fref="https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" rel='stylesheet')
//- script(src='https://cdn.bootcss.com/jquery/3.2.0/jquery.min.js')
//- script(src='https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/js/bootstrap.bundle.min.js')